Stator manufacturing method

ABSTRACT

Pivotal jaws of wire clamps that temporarily grip stator coil lead wires are spring biased to clamp stator coil lead wires thereto when the lead wires are inserted into the clamps at a winding station, and are biased by respective air actuators to ensure release of the lead wires at a coil lead terminating station.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 08/473,084,filed Jun. 7, 1995, now abandoned, which is a division of applicationSer. No. 08/219,847, filed March 30, 1994, of John M. Beakes andLawrence E. Newman, now U.S. Pat. No. 5,495,659.

FIELD OF INVENTION

This invention relates to a stator manufacturing method and, althoughnot necessarily so limited, is especially adapted for the manufacture of2-pole stators for electric motors or other electrical devices.

INCORPORATION BY REFERENCE

The disclosures of Alvin C. Banner et al. U.S. Pat. No. 5,090,108,granted Feb. 28, 1992, and John M. Beakes et al. U.S. Pat. No.5,186,405, granted Feb. 16, 1993, are hereby incorporated by referenceherein.

BACKGROUND OF THE INVENTION

Modern stator manufacturing production lines include several differentstations at which different manufacturing operations are performed. Onesuch operation that is frequently accomplished at an early stage in theprocess for manufacturing a 2-pole stator, is to assemble stator coilterminals or supports therefor on an unwound stator core. Thereafter,the stator coils are wound on the stator core pole pieces at a statorwinding station using magnet wire having an electrically insulatingcoating. A common practice in use at this time is to temporarily clampthe stator coil lead wires to wire clamps during the winding process. Ata later manufacturing stage, the lead wires are connected to theterminals mounted on the stator core at a coil lead terminating station.

One type of stator manufacturing machine, known as a turret winder, suchas the machine 50 disclosed in above-mentioned Beakes et al. U.S. Pat.No. 5,186,405, includes a turret by which unwound stators having coreson which terminal members have previously been assembled are moved to astator winding station at which the stator coils are wound and by whichthe freshly wound stators are then moved to a lead connect station atwhich the stator coil lead wires are connected to the terminal memberson the core. Lead pull assemblies at the winding station have wiregrippers which are manipulated to place the stator coil lead wires intotemporary wire clamps that are moved to a lead connect station alongwith the wound stator. Mechanisms at the lead connect station remove thestator coil lead wires and connect them to stator terminals or terminalsupport members on the stator core. As known to those familiar with thestator winding art, the same general method is practiced using differenttypes of mechanisms for transporting the stator from the winding stationto the coil lead terminating station, such as shown in the abovementioned Banner et al. U.S. Pat. No. 5,090,108.

Various temporary wire clamps have been used. A simple wire clamp havingjaws that are spring biased toward one another may be sufficient.However, wires temporarily held by a spring operated clamp mayoccasionally may remain stuck in the clamp and interfere with subsequentmanufacturing procedures. Wire clamps that are spring-biased opened andclosed by individual air actuators (one for each temporary clamp) havealso been used. By using air actuators to close the clamps it waspossible to ensure that wires of various different sizes would besecurely clamped. However, the air actuators had to be transferred withthe clamps and the expense, complexity, and space requirements for theair actuators and their controls made their use undesirable.

SUMMARY OF THE INVENTION

An object of this invention is to provide a stator manufacturing methodembodying an improved temporary wire clamp method by which stator coillead wires can not only be satisfactorily gripped but will alsoassuredly be released at the coil lead terminating station.

In accordance with this invention, the jaws of the temporary wire clampsare spring-biased closed and opened by air actuators which arepermanently located at the coil lead terminating station. Accordingly,the jaws of the temporary wire clamps will be sufficiently spaced apartwhen opened to assure that the coil lead wires will not remain grippedto them.

Other objects and advantages will become apparent from the followingdescription of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially diagrammatic, fragmentary, perspective view ofportions of a stator manufacturing and testing apparatus embodying theinstant invention.

FIG. 2 is an enlarged, partially exploded, fragmentary perspective viewof a portion of the apparatus shown in FIG. 1.

FIG. 3 is a fragmentary front elevational view of parts of the apparatusillustrated in FIG. 2 shown engaged with a stator coil lead wire.

FIG. 4 is a fragmentary side elevational view of the parts shown in FIG.3. Portions of FIG. 4 are shown in vertical cross section along line4--4 of FIG. 3.

FIG. 5 is a fragmentary cross sectional view similar to FIG. 4 but withparts shown at a stage of operation of the apparatus different from thatillustrated by FIG. 4.

FIG. 6 is a fragmentary side elevational view, with parts in crosssection, of another portion of the apparatus shown in FIG. 1. FIG. 6shows the parts as if viewed in the direction of arrows 6--6 of FIG. 1and along the section indicated thereby.

FIG. 6 further includes a phantom line representation of a movedposition of a tester terminal block.

FIG. 7 is a fragmentary, side elevational view, with parts broken awayand in cross section of parts of a stator manufacturing machine withwire clamps of a second embodiment in accordance with this invention.

FIG. 8 is an enlarged, fragmentary, front elevational view of a portionof the machine of FIG. 7.

FIG. 9 is a fragmentary side elevational view of the parts shown in FIG.8, but on a slightly smaller scale. Portions of FIG. 9 are shown invertical cross section along line 9--9 of FIG. 8.

DETAILED DESCRIPTION

With reference to FIG. 1, this invention is incorporated into a statormanufacturing and testing apparatus, generally designated 10, and isused to wind coils 12 formed from insulated magnet wire onto a 2-polestator 14, to test the coils 12 and their lead wires W, and to connectthe lead wires W to stator terminals or stator terminal supports 16mounted on the stator cores. All of the operations of the apparatus 10are synchronized and controlled by suitable machine controls,diagrammatically illustrated in FIG. 1. Such controls are known, may beconventional, and are not further described herein.

Apparatus 10 includes a turret plate 18 mounted for rotation about avertical axis 20 (in the manner illustrated in FIG. 7) and repeatedlyrotationally indexed through successive 90 degree increments in onedirection, as indicated by the arrow 22, about its vertical axis 20 by asuitable indexing drive motor 24. Stators to be wound are clamped to anindividual one of four stator support and clamp mechanisms, generallydesignated 26, to which they remain clamped throughout a complete cycleof operation of the apparatus of winding, testing, and lead connectingoperations.

The four stator clamp mechanisms 26 are connected to the turret plate 18at 90 degree spaced locations so that, in operation, after each 90degree index of the turret plate 18, there will be a clamp mechanism 26at each of four stations, namely a load/unload station A, an idlestation B, a winding station C, and a coil lead terminating station D.At each of the stations, the stators are positioned with their centeraxes extending horizontally and substantially perpendicularly withrespect to the vertical axis 20 of the turret plate 18 and with the endfaces of the stators most remote from the vertical axis 20 in verticalorientations and spaced a fixed horizontal distance from the verticalaxis 20 of the turret plate 18.

At the load/unload station A, a newly wound stator 14 is unclamped fromits support and clamp assembly 26, removed from the turret plate 18, andreplaced by an unwound stator 14. No operations are performed on thestator at the idle station B. At the winding station C, a pair of statorcoils are wound by the operation of a winding head 30 located adjacentthe winding station C that has a reciprocating and oscillating shuttleor ram 32 that draws wires from sources (not shown) of wire undertension and having wire guide needles 34 through which the wires exit asthe coils are wound. The winding shuttle or ram 32 reciprocates andoscillates about a fixed horizontal axis in order to wind coils of wirearound the stator pole pieces in a manner well known in the art.

At or about the time of the commencement of the winding of a pair ofcoils 12, the stator lead wires, known as "start wires," are insertedinto a pair of temporary wire clamps 36 by the operation of a pair ofmovable wire grippers 38, which are preferably of the type shown in saidU.S. Pat. No. 5,186,405. At the conclusion of the winding operation, thewire portions leading from the coils to the winding shuttle 32 aregripped by the wire grippers 38 to form coil finish lead wires extendingfrom the coils 12, which are then positioned in other ones of the wireclamps 36. Wire cutting mechanisms associated with the wire grippers 38cut the finish leads free from the wire grippers 38 so that the newlywound stator 14 is completely free from the winding shuttle 32. Thewound stator 14 is then indexed by rotation of the turret plate 18 tothe wire terminating station D at which the stator is electricallytested and the start and finish leads are removed from the wire clamps36 and at least temporarily connected to terminals on the stator 14 by arobot 40 having a wire-gripping and manipulating end effector 42. Therobot 40 may also be conventional and is not further described herein.Thus it may be seen that, when the newly wound stator returns to theload/unload station A, it may be simply unclamped from the turret plate18 and removed. The foregoing operations are repeated to continuouslywind stators.

At each turret station, the temporary wire clamps 36 are mounted on aclamp mounting plate 44 made from an insulating material, such as aphenolic resin or other plastic material, and which in turn is mountedon the outwardly facing edge surfaces of a mutually-spaced pair ofsupport plates 46 and 48 affixed to the turret plate 18 by screws 50.The support plates 46 may be referred to as the leading plates withreference to the direction of rotation of the turret plate 18 indicatedby the arrow 22.

With reference to FIGS. 2 through 5, each temporary wire clamp 36includes a pair of wire clamp members, namely a fixed clamp member 52and a movable or pivotal clamp member 54. The pivotal clamp member 54and, optionally, the fixed clamp member 52, are made from a hardenedtool steel or other suitable electrically conductive material. Fixedclamp member 52 is fixedly mounted on the clamp mounting plate 44 byscrews 56 and comprises a body member having a horizontal jaw 58 and abifurcated portion abutting the clamp mounting plate 44 that forms aclevis yoke 60 through which a clevis pin 62 extends. Clevis pin 62,which may simply be a shoulder screw, has a threaded end engaged in atapped hole 64 in one of the bifurcations of the clevis yoke 60. Thepivotal clamp member 54 comprises an L-shaped body member having agenerally vertical leg 66 pivotally supported by the clevis pin 62.Pivotal clamp member 54 further includes a generally horizontal, movableclamp jaw 68 that confronts the fixed clamp jaw 58.

A clamp spring 70 is mounted partly within a through bore 72 in thefixed clamp member 52 and has one end which bears against the outwardlyfacing surface of the vertical leg 66 of the pivotal clamp member 54.The other end of the clamp spring 70 abuts against the inner end of aretaining screw 74 which is located in the tapped, outer end of thethrough bore 72. Clamp spring 70 is under compression so that it pushesagainst the vertical leg 66 of the pivotal clamp member 54, which causesthe pivotal clamp jaw 68 to be pressed against the fixed jaw 58.

Accordingly, a lead wire W inserted between the fixed jaw 58 and themovable jaw 68 will be securely clamped between the jaws 58 and 68, asis shown in FIG. 4.

With reference to FIGS. 4 and 5, in order to release the clamped wirefrom a temporary clamp 36, a release pin 76 is fixed in the vertical leg66 of the pivotal movable clamp member 54 and extends rearwardlycompletely through and beyond a through bore 78 in the clamp mountingplate 44. An air operated clamp release actuator 80 is energized toextend a fitting 82 at the end of its piston rod into engagement withthe rearwardly projecting end of the release pin 76 and thereby overcomethe bias of the clamp spring 70 and reversely pivot the pivotal clampmember 54 so that its jaw 68 moves away from the fixed jaw 58 as shownin FIG. 5. For reasons which will become apparent, the piston rodfitting 82 is preferably made from a plastic insulating material or elsehas an insert (not shown) made of such material that engages the releasepin 76 so that there can be no accidental electrical connection betweenthe release pin 76 and the clamp release actuator 80.

As shown in FIG. 1, there are four clamp release actuators 80, one foreach temporary clamp 36, mounted on a vertical support plate 84 that isfixed and does not rotate with the turret plate 18. Therefore, the clamprelease actuators remain adjacent the testing and lead wire connectstation D at all times. Here it may be noted that there are occasionswhen more than four temporary clamps 36 may be used, particularly forstators having coils with intermediate taps. As is obvious, there wouldthen be more than four clamp release actuators 80.

In the embodiment of this invention shown in FIGS. 1 through 6, theconfronting surfaces of the fixed clamp jaw 58 and the movable clamp jaw68 are contoured not only to firmly grip the lead wire segments W butalso to scrape away the insulating coating on the lead wires as they areinserted therein. By scraping away the insulation in this manner, anelectrical connection is formed between each lead wire and itsassociated pivotal clamp member 54. With continued reference to FIGS. 2through 5, the mutually confronting surfaces of the fixed clamp jaw 58and the movable clamp jaw 68 are contoured to have beveled outer ends bywhich the lead wire segments W are guided therebetween as a result ofthe movements of the lead wire grippers 38. In addition, the fixed clampjaw 68 has a shallow, longitudinally-extending groove 86 confronting thepivotal jaw 68 and the pivotal jaw 68 has beveled side faces that joinat a longitudinally-extending knife edge 88 that confronts the center ofthe shallow groove 86 in the fixed clamp jaw 58. As a result of thisconstruction, the insulating coating on a lead wire is stripped away bythe knife edge 88 as the lead wire is being inserted between the clampjaws 58 and 68 by operation of the wire grippers 38 into the positionillustrated in FIGS. 3 and 4. Here, it may be noted as apparent that theclamp springs 70 must be sufficiently strong to hold the pivotal clampjaws 54 in position to effect the scraping away of the insulatingcoating on the lead wires as described above.

As best illustrated in FIGS. 1, 2, 3 and 6, each pivotal clamp jaw 68 iselectrically connected to an electrical terminal member 90 mounted on aterminal block 92 which itself is mounted on the associated leadingsupport plate 46. Such electrical connection is provided by means of aninsulated connector wire 94 connected at one end to a mounting screw 96projecting from the pivotal clamp and connected at its other end to theterminal member 90. Terminal member 90 may conveniently comprise a brassscrew, the head 98 of which has been faced off flat. Terminal screw head98 projects out the front side of terminal block 92 so that it can beengaged by a cooperating tester terminal member 100 aligned therewith.Insulated connector wires 94 are clamped to the mounting plate 44 bysuitable clips 102 and extend through to the backside of the mountingplate 44 and around the top rear of the mounting plate 44 to theirassociated clamp terminals 90 on the terminal block 92.

With reference to FIG. 1, there is one tester terminal member 100aligned with each of the clamp terminal members 90. Tester terminalmembers 100 are preferably made from square brass rod material and areheld within square bores in the front and rear walls of a testerterminal housing 104 so that they cannot rotate. An intermediate portionof each tester terminal member 100 is grooved for connection of asuitable retaining ring 106, such as an e-ring or a c-clip, thereto andis surrounded by a coil spring 108. All of the retaining rings 106 andthe coil springs 108 are located within a hollow compartment 110 withinthe tester terminal housing 104 with the springs 108 placed undercompression so that the retaining rings 106 and, accordingly, the testerterminal members 100 are biased toward the clamp terminal members 90.Therefore, the tester terminal housing 104 can be advanced, as will bedescribed below, toward the clamp terminals 90 to the point at which thetester terminal springs 108 are further compressed so that goodelectrical contact is effected between the clamp terminals 90 and thetester terminals 100. The ends of the tester terminals 100 are connectedby connector wires 111 to an electric test console 112 which performssuch electrical tests on the coils 12 and their lead wires as aredesired. Preferably such tests are carried out automatically and, in theevent of a failure, operation of the winding and testing apparatus 10 isinterrupted until the problem which caused the test failure can becured. The nature of the tests and the mechanical and electronicconstruction of the test console 112 may be conventional and form nopart of this invention. Assuming the test results are acceptable, thetester terminal housing 104 is retracted from the turret 18, causing adisconnection of the tester terminals 100 from the clamp terminals 90,and the robot 40 is then energized to effect connection of the coil leadwires to the terminals or terminal supports 16.

The tester terminal housing 104 is mounted on a stanchion 114 projectingupwardly from an L-shaped, tooling support arm 116 which is driventoward and away from the turret plate 18 in order to effect electricalconnection and disconnection of the tester terminal members 100 with theclamp terminals 90 by means of a tooling positioning actuator 118, whichis preferably a double-acting linear air actuator, mounted on animmovable support member 120. A second air actuator 122 is shown mountedon the immovable support member 120. It can be used to prevent overtravel or to reversely position the tooling support arm 116, and is notessential to the operation of the apparatus of this invention.

To reduce the load on the tooling actuator 118, the stanchion 114 andits support arm 116 are preferably made from aluminum or otherlightweight metal. To resist damage to the aluminum material, a steelinsert (not shown) can be mounted in the support arm 116 aligned withthe piston rod of the second air actuator 122 in the event the latteractuator 122 may be used to position the support arm 116. The supportarm 116 can be connected by screws (not shown) to a mounting plate 124connected to the piston and guide rods projecting from the tooling 118.To resist having the support arm 118 twist or sag, it preferably isformed with a channel in which the mounting plate 124 is snuglyreceived.

With reference to FIGS. 7, 8 and 9, a second embodiment of a statormanufacturing machine, generally designated 130, in accordance with thisinvention is illustrated. Like reference numbers are applied to parts ofthe machine of FIGS. 7, 8 and 9 which may correspond identically toparts in FIGS. 1 through 6. Machine 130 is the same machine as themachine 10 of FIGS. 1 through 6 except that no provision is made forelectrically testing the stator coils at the coil lead terminatingstation and the wire clamps, generally designated 132 in FIGS. 7, 8 and9, have conventional confronting wire clamping surfaces 134 and 136which are not designed to remove the insulating coating from the coillead wires.

In this second embodiment, the temporary wire clamps 132 are mounted onclamp mounting plates 138, which could be made from aluminum or othersuitable material and need not be made from an electrical insulatingmaterial, and which are mounted on the outwardly facing edge surfaces ofmutually-spaced pairs of support plates 46 and 48 affixed to the turretplate 18. Although only two wire clamps 132 are illustrated in FIG. 7,it is to be understood that, as in the case of the first embodiment,there will be four or more wire clamps supported by each clamp mountingplate 138.

With reference to FIGS. 8 and 9, each temporary wire clamp 132 includesa pair of wire clamp members, namely a fixed clamp member 140 and amovable or pivotal clamp member 142. Fixed clamp member 140, which isfixedly mounted on the clamp mounting plate 138 by screws 144 andcomprises a body member having a horizontal jaw 146 and a bifurcatedportion abutting the clamp mounting plate 138 that forms a clevis yoke148 through which a clevis pin 150 extends. The pivotal clamp member 142comprises an L-shaped body member having a generally vertical leg 152pivotally supported by the clevis pin 150. Pivotal clamp member 142further includes a generally horizontal, movable clamp jaw 154 thatconfronts the fixed clamp jaw 146. Clamp jaw 154 has a relieved clampingsurface 156 intermediate its ends so that a tooth 158 is effectivelyformed at its outer end. The provision of such a tooth is not new and isknown to be effective for better retaining lead wires against accidentalremoval.

A clamp spring 156 is mounted partly within a through bore 158 in thefixed clamp member 140 and has one end which bears against the outwardlyfacing surface of the vertical leg 152 of the pivotal clamp member 142.The other end of the clamp spring 156 abuts against the inner end of aretaining screw 160 which is located in the tapped, outer end of thethrough bore 158. Clamp spring 156 is under compression so that itpushes against the vertical leg 152 of the pivotal clamp member 142,which causes the pivotal clamp jaw 154 to be pressed against the fixedjaw 146. Accordingly, a lead wire (not shown) inserted between the fixedjaw 146 and the movable jaw 154 will be securely clamped between thejaws 146 and 154.

With reference to FIGS. 8 and 9, in order to release the clamped wirefrom a temporary clamp 132, a release pin 162 is fixed in the verticalleg 152 of the pivotal movable clamp member 142 and extends rearwardlycompletely through and beyond a through bore 164 in the clamp mountingplate 138. As in the first embodiment, an air operated clamp releaseactuator 80 is energized to extend a fitting 82 at the end of its pistonrod into engagement with the rearwardly projecting end of the releasepin 162 and thereby overcome the bias of the clamp spring 156 andreversely pivot the pivotal clamp member 142 so that its jaw 154 movesaway from the fixed jaw 146 when the lead wire gripped thereby is toreleased.

As before in the embodiment of FIGS. 1 through 6, there are four clamprelease actuators 80, one for each temporary clamp 132. Except that theembodiment of FIGS. 7 through 9 is not capable of performing anelectrical test procedure, the operation of the embodiment of FIGS. 7, 8and 9 is the same as in the embodiment of FIGS. 1 through 6.

In the practice of this invention using a robot 40 with an end effector42, after a wound stator is transferred to the coil lead terminatingstation, a first lead wire is gripped by the robot end effector and, bymanipulation of the end effector, connected to a terminal device on thestator core. The remaining lead wires are gripped in seriatim by the endeffector and connected to their respective terminal devices. Each of thepivotal clamp jaws is pivoted by its associated said air actuatorimmediately after the associated lead wire is gripped by said endeffector to ensure release of the lead wires from the clamps.

Although the presently preferred embodiments of this invention has beendescribed, it will be understood that within the purview of theinvention various changes may be made within the scope of the followingclaims.

I claim:
 1. A stator manufacturing method comprising the stepsof:supporting a stator core on a support member at a winding station;winding coils of insulated magnet wire onto said stator core whileinserting coil lead wires extending to and from said coils between afixed jaw and a movable jaw of respective temporary wire clampssupported in fixed relation to said support member, said pivotal jawsbeing spring biased to grip said lead wires; transferring said supportmember with said stator supported thereon along with said temporary wireclamps from said winding station into a coil lead terminating station;attaching said lead wires to stator terminals or terminal supports atsaid coil lead terminating station; and moving said movable clamp jawsaway from said fixed clamp jaws by engaging said movable clamp jaws byair actuators located adjacent said coil lead terminating station. 2.The method of claim 1 wherein said attaching step is accomplished bygripping said lead wires seriatim by a robot end effector andmanipulating said end effector with the wires gripped thereby, andwherein each of said movable clamp jaws is moved by its associated oneof said air actuators immediately after the associated lead wire isgripped by said end effector.
 3. The method of claim 1 wherein saidstator is supported on a rotatable turret and said transferring step iscarried out by rotating said turret.
 4. The method of claim 3 whereinsaid attaching step is accomplished by gripping said lead wires seriatimby a robot end effector and manipulating said end effector with thewires gripped thereby, and wherein each of said movable clamp jaws ismoved by its associated one of said air actuators immediately after theassociated lead wire is gripped by said end effector.
 5. The method ofclaim 1 wherein said movable clamp jaw is pivotal relative to said fixedclamp jaw, and wherein said moving steps comprises pivoting said pivotalclamp jaw away from said fixed clamp jaw.
 6. The method of claim 2wherein said movable clamp jaw is pivotal relative to said fixed clampjaw, and wherein said moving steps comprises pivoting said pivotal clampjaw away from said fixed clamp jaw.
 7. The method of claim 3 whereinsaid movable clamp jaw is pivotal relative to said fixed clamp jaw, andwherein said moving steps comprises pivoting said pivotal clamp jaw awayfrom said fixed clamp jaw.
 8. The method of claim 4 wherein said movableclamp jaw is pivotal relative to said fixed clamp jaw, and wherein saidmoving steps comprises pivoting said pivotal clamp jaw away from saidfixed clamp jaw.